Means for densifying metallic surfaces.



0. WADSWORTH.

NNNNNN OR SSSSSSS ES F. L. 0. WADSWORTH.

MEANS FOR DENSIFYING METALLIC SURFACES.

APPLIG 6, 1911. jifl'yl ggg Patented Oct. 7, 1913.

2 SHEETSSHBET 2.

W' Li 33 VENT FRANKL. Oi WADSWOR'IH; OF SEWICKLEY; PENNSYLVANIA.

MEANS; EQRL-DENSBEYINGPMEWA'LLIG .SUIRFAGEB.

Specification of Letters Tatum;

Patented Oct. '7, 1913.

Application filed February 6, 1911. Serial Km 606,898.

To all whom it may concern Bait-known that-I, F RANKUL. .O. VVADS-wmrrn,residingat Sewickley, in the county.

of Alleghenv and .State of Pennsylvania, a

citizen of tlieUnited States, have inventedor discovered certain :newand-'use ful Improvements in Means fr Densi'fyi-ng .MetallieSurfaoes,-of which improvementstl-ie following is a specification.

The-invention relates tothe densification of the surface portions ofmetallic articles, and has-for -its object the provision of improvedmeans for effecting such densification, and .in a moreithorough andefficient manner.

The surfaces of metallic articles have heretofore beeni-densifiedbyfirst rolling upon said surfaces closely arranged projections anddepressions, and then rollingdown the roughened surfaces between smoothrolls. The rolls for roughening the surfaces of the metal piece haveusually been marked by cutting their operating surfaces in annulargrooves and cross-grooves, thus forming upon them a multiple ofprojections of a quadrilateral cross-section. By marking the rolls ashereinafter described the expense of marking is reduced, the pattern ismore durable, and a more effective and thorough densification of theproduct is attained.

In the accompanying drawings Figure 1 is a plan View of a portion of aroll or other die surface embodying the invention; Fig. 2 is across-section on the line 11-11 of Fig. 1; Fig. 3 is a cross-section onthe line IIIIII of Fig. 1; Fig. 4 is a View in elevation of a stand ofrolls suitable for the practice of the invention, the reduced scalehowever not permitting a complete portrayal of the marking; Fig. 5 is aperspective view of a portion of one surface of a metal plate' afterhaving been subjected to the action of one of the marked roll-surfaces;Fig. 6 is a View similar to Fig. 1 illustrating a modified form ofmarking; Fig. 7 is a cross-section on the line VII-VII of Fig. 6; Fig. 8isa view similar to Fig. 5 of the surface of the product of the roll ordie of Fig. 6; Fig. 9 illustrates conventionally the roughening androlling down of the surface of a piece of metal.

In the embodiment of the invention illustrated in Fig. 1, the roll orother die surface for roughening the surface of the metal piece iscovered with pyramidal indentations 1 of triangular cross-section.Theseindenta- :tLO'IlS a-PeOf uniform dimensions and are arranged inrows,--edge to edge, with the apices of the triangular edges of adjacentindentatrons in. each. row pointing inopposite direct1ons,- and eacharranged apex to apex' and base to base with like indentationsv in thead acent rows. Thus, as shown, the edges of the indentationstogetherfor-m transverse and. diagonal intersecting. ridges or facets 2,symmetrically; disposed over the entire marked surface of the roll ordie.

The operating surfaces of-the rolls 3, 4 and-5 ofthe stand shown in Fig.4, which form. the-four initial passes a, I), 0 and 0!,

.may all. be marked in themanner-described,

with indentations gradually. decreasing in dimensions at each succeedingpass. The surface of the lower roll 3 in the fifth pass 6 may. also bemarked as shown, while the surfaces of the rolls 4 and 5 forming thesixth pass f will be left smooth. It will be understood however thateither or both surfaces of the piece may be roughened in as many or asfew passes as may be desired, and may be smoothed in another pass in thesame stand of rolls or in a separate stand.

In the use of a stand of rolls such as is shown in Fig. 1, for theformation and treatment of a flat plate or strip of metal, the pieceafter having been heated is first fed forward through the lower pass a,whence it emerges with both of its fiat surfaces cove-red by upstandingadjacent pyramidal projections 6, as shown in Fig. 5, with their basesabutting against each other, and all faces of each projection exposed tothe effect of the air or other substance with which these markedsurfaces may be brought into contact. The piece is then returned throughthe upper pass I) and the operation repeated, as also in the next passes0 and d. In the fifth pass 6 the projections upon the upper face of thepiece will be smoothed down, and in the final pass f the projections onthe lower face will be smoothed. In this final compression of thepyramidally .marked surfaces each to a smooth surface,

there will be a material densification of the surface portions of thepiece in lines parallel with the general plane of its surface.

In Fig. 6 there is illustrated another arrangement of the indentationsin the die surface, the edges of corresponding indent-ations in adjacentrows facing in the same 7 each indentation strikes the center of thedirection, so that the apex of the edge of base of the edge of anindentation in the next row.

. By marking the operating surface of the roll or die With pyramidalindentations, with the edges of adjacent indentations coinciding asdescribed, a much stronger and more durable die surface is obtained thanin the case of a surface provided With separate and distinctprOjectio-ns, while at the same time the maximum Working and densify'ingaction is insured. While the indentations may have more than threefaces, it is preferred to make them of triangular crosssection asdescribed, since there is thereby obtained a maximum of operativesurface area for a given mass of metal. Thus not only is the metal piecemost effectively Worked, but it is given a ver large surface areaexposed to the cooling e ect of the rolls and of the surroundingatmosphere. I

-I claim as my invention: l. A die for use in the process of densifyingthe surfaces of metallic articles by first roughening and then smoothingthe surface to be densified, having formed 1n its operat ing surfaceclosely adjacent pyramidal indentations. I

2. A die for use in the process of densify- ,ing the surfaces ofmetallic articles by first roughening and then smoothing the surface tobe densified, havin formed in its operating surface pyrami alindentations, each edge of each indentation coinciding with an edge ofan adjacent indentation. V

3. A die for use in the process of densifying the surfaces of metallicarticles by first roughenin and then smoothing the surface to bedensified, having formed in its operating surface pyramidal indentationsof triangular cro'ss-section arranged edge to edge.

at; A rolling mill for densifying the surfaces of metallic articles,having formed in the surface of one pass pyramidal indentations oftriangular cross-section arranged edge to edge, and having asmooth-surfaced succeeding pass. i

In testimony whereof I have hereunto set my hand.

FRANK L. O. WADSWORTH. Witnesses: v

G. G. Tana, FRANCIS J. ToMAssoN.

